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Immunotoxicity of heavy metals and PCB S on echinoderms
Abstmcts / Compurntive Biochrmistt~ and Physiology, Part A 126 (2000) SI-S163
METABOLIC BUDGET OF AN ESSENTIAL AND A NON-ESSENTIAL DIETARY ACID IN HERRING (CLUPEA HARENGUS) LARVAE Conceic2o L.E.C.‘, Tonheim SK2 and Ronnestad I.2 ‘CCMAR, University of Algarve, Portugal; 2 Dept. Zoology, University of Bergen, Norway
s31
AMINO
In comparison to mammals, juvenile and adult fish have a higher amino acid (AA) requirement and a lower adaptability of AA metabolism. This means that fish are more sensitive to diets with low protein levels or with an imbalanced AA profile. Fish larvae are thought to have even less control of their AA metabolism, leading to higher catabolic losses of AA, and thereby to higher AA requirements (Dabrowski 1986). Therefore it is important to know to what extent fish larvae have the ‘ydpacity to spare essential AA (EAA) at the expenses of non-essential AA (NEAA). ‘This study intended to estimate a metabolic budget both for an EAA and a NEAA, in herring (Clupen harengus) larvae. A nlix of crystalline amino acids containing either ‘“C-Glutamate or 14C-Lysine was tube-feed to first feeding and 47 days-old Ipre-metamorphosis) in herring larvae. The following components of the metabolic budget were estimated: AA digestive absorption, AA conversion into lipidic molecules, AA oxidation, and conservation of AA in the FAA and in the protein pools. l-‘lrst feeding herring larvae absorbed around 92% of both lysine and glutamate. However, 23 % of the tube-feed lysine was ouidised and 69% was retained while for glutamate oxidation was as high as 76% and retention only 16%. A similar picture was observed for 47 days-old larvae. Here oxidation was 22% and 62% and retention 63% and 32%, for lysine and glutamate, respectively. Therefore, herring larvae use glutamate preferentially to lysine for energy production from first feeding onwards. These results suggest that fish larvae may have a better capacity of regulating AA catabolism than previously believed (Concei@o et al. 1997, 1998). Conce@o, L.E.C. et al. (I 997) Amino acid metabolism and protein turnover in larval turbot (Scophthalmus mmimus) fed natural zooplankton or Artemia. Mar. Biol.29. 25526.5. Concei@o, L.E.C et a1.(1998). Amino acid profiles and amino acid utilisation in larval African catfish (Clurias gariepinus): effects of ontogeny and temperature. Fish Physiol. Biochem 19: 43-47. Dabrowski, K.R. (1986) Comp. Biochem. Physiol. &5J: 639-655.
IMMUNOTOXICITY
OF HEAVY METALS AND PCB S ON ECHINODERMS
(zoteur G., Dank B., Warnau M., Jangoux M. and Dubois P. Laboratoire de Biologie Marine, CP 160/15, Universitk Libre de Bruxelles 50, Av. F. Roosevelt, 1050 Bruxelles Xcnobiotic-induced environment, a fact echinoderm phylum the immune system
B-
immunotoxicity has been implied in the outbreak of several invertebrate diseases in the marine that prompted studies in several phyla. However, although ecotoxicology has extensively addressed the and despite the ecological importance of several members of this group, the impact of xenobiotics on in this phylum has scarcely been assessed.
Echinoderms, as other invertebrates, lack the adaptive immune responses of higher vertebrates. Their immune response almost entirely supported by circulating coelomocytes responsible for humoral as well as cellular responses comparable those carried out by vertebrate mononuclear phagocytes. Major cellular responses include phagocytosis and production reactive oxygen species (ROS). The goal of the present study is to determine the effects of heavy metals and PCB’s these responses in echinoderms during experimental contaminations and in field studies.
is to of on
The phagocytic activity of the seastar Aster& rubens was not affected during short-term experimental contaminations, neither by heavy metals nor by PCB’s. This is in contrast with studies conducted in polluted areas. Indeed, the phagocytic activity of coelomocytes from A. rubens near the Scheldt estuary (Belgium - The Netherlands) was significantly correlated with the contamination level of the animals. In the bay of Portman (Mediterranean, Spain), phagocytosis by coelomocytes from the seastar Echinaster sepositus and the sea urchin Paracentvotus lividus, collected along a gradient of metal pollution, was affected by the environmental contamination. The ROS production upon antigenic stimulation (the so-called respiratory burst) was found to be highly sensitive to xenobiotics. This immune response increased in both A. rubens and P. lividus contaminated by heavy metals and PCB’s in experimental conditions. On the contrary, significant reductions of this response were found in A. rubens collected along a pollution gradient off the Elbe estuary and in the area of the Scheldt estuary. It is concluded that echinoderms can be affected by xenobiotics and that the impact varies depending on the immune response and the species considered. This emphasises the need for a multi-assay and a multi-model approach of immunotoxicology in marine invertebrates.
METABOLIC BUDGET OF AN ESSENTIAL AND A NON-ESSENTIAL DIETARY ACID IN HERRING (CLUPEA HARENGUS) LARVAE Conceic2o L.E.C.‘, Tonheim SK2 and Ronnestad I.2 ‘CCMAR, University of Algarve, Portugal; 2 Dept. Zoology, University of Bergen, Norway
s31
AMINO
In comparison to mammals, juvenile and adult fish have a higher amino acid (AA) requirement and a lower adaptability of AA metabolism. This means that fish are more sensitive to diets with low protein levels or with an imbalanced AA profile. Fish larvae are thought to have even less control of their AA metabolism, leading to higher catabolic losses of AA, and thereby to higher AA requirements (Dabrowski 1986). Therefore it is important to know to what extent fish larvae have the ‘ydpacity to spare essential AA (EAA) at the expenses of non-essential AA (NEAA). ‘This study intended to estimate a metabolic budget both for an EAA and a NEAA, in herring (Clupen harengus) larvae. A nlix of crystalline amino acids containing either ‘“C-Glutamate or 14C-Lysine was tube-feed to first feeding and 47 days-old Ipre-metamorphosis) in herring larvae. The following components of the metabolic budget were estimated: AA digestive absorption, AA conversion into lipidic molecules, AA oxidation, and conservation of AA in the FAA and in the protein pools. l-‘lrst feeding herring larvae absorbed around 92% of both lysine and glutamate. However, 23 % of the tube-feed lysine was ouidised and 69% was retained while for glutamate oxidation was as high as 76% and retention only 16%. A similar picture was observed for 47 days-old larvae. Here oxidation was 22% and 62% and retention 63% and 32%, for lysine and glutamate, respectively. Therefore, herring larvae use glutamate preferentially to lysine for energy production from first feeding onwards. These results suggest that fish larvae may have a better capacity of regulating AA catabolism than previously believed (Concei@o et al. 1997, 1998). Conce@o, L.E.C. et al. (I 997) Amino acid metabolism and protein turnover in larval turbot (Scophthalmus mmimus) fed natural zooplankton or Artemia. Mar. Biol.29. 25526.5. Concei@o, L.E.C et a1.(1998). Amino acid profiles and amino acid utilisation in larval African catfish (Clurias gariepinus): effects of ontogeny and temperature. Fish Physiol. Biochem 19: 43-47. Dabrowski, K.R. (1986) Comp. Biochem. Physiol. &5J: 639-655.
IMMUNOTOXICITY
OF HEAVY METALS AND PCB S ON ECHINODERMS
(zoteur G., Dank B., Warnau M., Jangoux M. and Dubois P. Laboratoire de Biologie Marine, CP 160/15, Universitk Libre de Bruxelles 50, Av. F. Roosevelt, 1050 Bruxelles Xcnobiotic-induced environment, a fact echinoderm phylum the immune system
B-
immunotoxicity has been implied in the outbreak of several invertebrate diseases in the marine that prompted studies in several phyla. However, although ecotoxicology has extensively addressed the and despite the ecological importance of several members of this group, the impact of xenobiotics on in this phylum has scarcely been assessed.
Echinoderms, as other invertebrates, lack the adaptive immune responses of higher vertebrates. Their immune response almost entirely supported by circulating coelomocytes responsible for humoral as well as cellular responses comparable those carried out by vertebrate mononuclear phagocytes. Major cellular responses include phagocytosis and production reactive oxygen species (ROS). The goal of the present study is to determine the effects of heavy metals and PCB’s these responses in echinoderms during experimental contaminations and in field studies.
is to of on
The phagocytic activity of the seastar Aster& rubens was not affected during short-term experimental contaminations, neither by heavy metals nor by PCB’s. This is in contrast with studies conducted in polluted areas. Indeed, the phagocytic activity of coelomocytes from A. rubens near the Scheldt estuary (Belgium - The Netherlands) was significantly correlated with the contamination level of the animals. In the bay of Portman (Mediterranean, Spain), phagocytosis by coelomocytes from the seastar Echinaster sepositus and the sea urchin Paracentvotus lividus, collected along a gradient of metal pollution, was affected by the environmental contamination. The ROS production upon antigenic stimulation (the so-called respiratory burst) was found to be highly sensitive to xenobiotics. This immune response increased in both A. rubens and P. lividus contaminated by heavy metals and PCB’s in experimental conditions. On the contrary, significant reductions of this response were found in A. rubens collected along a pollution gradient off the Elbe estuary and in the area of the Scheldt estuary. It is concluded that echinoderms can be affected by xenobiotics and that the impact varies depending on the immune response and the species considered. This emphasises the need for a multi-assay and a multi-model approach of immunotoxicology in marine invertebrates.